From 12f3dfd022d7e616757a94f0538d3d525d806a16 Mon Sep 17 00:00:00 2001
From: Ming Lei <tom.leiming@gmail.com>
Date: Thu, 16 Jul 2009 15:44:29 +0200
Subject: [PATCH] lockdep: Add statistics info for max bfs queue depth
Add BFS statistics to the existing lockdep stats.
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1246201486-7308-10-git-send-email-tom.leiming@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
kernel/lockdep.c | 6 +++++-
kernel/lockdep_internals.h | 3 ++-
kernel/lockdep_proc.c | 2 ++
3 files changed, 9 insertions(+), 2 deletions(-)
diff --git a/kernel/lockdep.c b/kernel/lockdep.c
index 6358cf7e84b2..744da6265d99 100644
--- a/kernel/lockdep.c
+++ b/kernel/lockdep.c
@@ -929,7 +929,7 @@ static int add_lock_to_list(struct lock_class *class, struct lock_class *this,
unsigned long bfs_accessed[BITS_TO_LONGS(MAX_LOCKDEP_ENTRIES)];
static struct circular_queue lock_cq;
-
+unsigned int max_bfs_queue_depth;
static int __bfs(struct lock_list *source_entry,
void *data,
int (*match)(struct lock_list *entry, void *data),
@@ -975,6 +975,7 @@ static int __bfs(struct lock_list *source_entry,
list_for_each_entry(entry, head, entry) {
if (!lock_accessed(entry)) {
+ unsigned int cq_depth;
mark_lock_accessed(entry, lock);
if (match(entry, data)) {
*target_entry = entry;
@@ -986,6 +987,9 @@ static int __bfs(struct lock_list *source_entry,
ret = -1;
goto exit;
}
+ cq_depth = __cq_get_elem_count(cq);
+ if (max_bfs_queue_depth < cq_depth)
+ max_bfs_queue_depth = cq_depth;
}
}
}
diff --git a/kernel/lockdep_internals.h b/kernel/lockdep_internals.h
index b115aaa0bf35..6baa8807efdd 100644
--- a/kernel/lockdep_internals.h
+++ b/kernel/lockdep_internals.h
@@ -138,6 +138,7 @@ extern atomic_t nr_find_usage_backwards_recursions;
#endif
+extern unsigned int max_bfs_queue_depth;
extern unsigned long nr_list_entries;
extern struct lock_list list_entries[MAX_LOCKDEP_ENTRIES];
extern unsigned long bfs_accessed[];
@@ -191,7 +192,7 @@ static inline int __cq_dequeue(struct circular_queue *cq, unsigned long *elem)
return 0;
}
-static inline int __cq_get_elem_count(struct circular_queue *cq)
+static inline unsigned int __cq_get_elem_count(struct circular_queue *cq)
{
return (cq->rear - cq->front)&(MAX_CIRCULAR_QUE_SIZE-1);
}
diff --git a/kernel/lockdep_proc.c b/kernel/lockdep_proc.c
index d7135aa2d2c4..9a1bf34d2ff6 100644
--- a/kernel/lockdep_proc.c
+++ b/kernel/lockdep_proc.c
@@ -411,6 +411,8 @@ static int lockdep_stats_show(struct seq_file *m, void *v)
max_lockdep_depth);
seq_printf(m, " max recursion depth: %11u\n",
max_recursion_depth);
+ seq_printf(m, " max bfs queue depth: %11u\n",
+ max_bfs_queue_depth);
lockdep_stats_debug_show(m);
seq_printf(m, " debug_locks: %11u\n",
debug_locks);
--
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